Endoplasmic reticulum membrane remodeling by targeting reticulon-4 induces pyroptosis to facilitate antitumor immune.

Mei-Mei ZHAO; Ting-Ting REN; Jing-Kang WANG; Lu YAO; Ting-Ting LIU; Ji-Chao ZHANG; Yang LIU; Lan YUAN; Dan LIU; Jiu-Hui XU; Peng-Fei TU; Xiao-Dong TANG; Ke-Wu ZENG

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Endoplasmic reticulum membrane remodeling by targeting reticulon-4 induces pyroptosis to facilitate antitumor immune.

Author: Mei-Mei ZHAO ¹ ; Ting-Ting REN ² ; Jing-Kang WANG ¹ ; Lu YAO ¹ ; Ting-Ting LIU ¹ ; Ji-Chao ZHANG ¹ ; Yang LIU ³ ; Lan YUAN ⁴ ; Dan LIU ⁴ ; Jiu-Hui XU ² ; Peng-Fei TU ¹ ; Xiao-Dong TANG ² ; Ke-Wu ZENG ¹
Author Information

1. State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100191, China.
2. Beijing Key Laboratory of Musculoskeletal Tumor, Peking University People's Hospital, Beijing 100044, China.
3. Center of Basic Medical Research, Institute of Medical Innovation and Research, Peking University Third Hospital, Beijing 100191, China.
4. Proteomics Laboratory, Medical and Healthy Analytical Center, Peking University Health Science Center, Beijing 100191, China.
Publication Type:Journal Article
Keywords: ER membrane; antitumor immune; chemical degrader; osteosarcoma; pyroptosis; reticulon-4 (RTN4)
MeSH: Pyroptosis/immunology*; Humans; Endoplasmic Reticulum/immunology*; Animals; Nogo Proteins/antagonists & inhibitors*; Mice; Cell Line, Tumor; Xanthones/pharmacology*; Neoplasms/pathology*; Mice, Nude
From: Protein & Cell 2025;16(2):121-135
CountryChina
Language:English
Abstract: Pyroptosis is an identified programmed cell death that has been highly linked to endoplasmic reticulum (ER) dynamics. However, the crucial proteins for modulating dynamic ER membrane curvature change that trigger pyroptosis are currently not well understood. In this study, a biotin-labeled chemical probe of potent pyroptosis inducer α-mangostin (α-MG) was synthesized. Through protein microarray analysis, reticulon-4 (RTN4/Nogo), a crucial regulator of ER membrane curvature, was identified as a target of α-MG. We observed that chemically induced proteasome degradation of RTN4 by α-MG through recruiting E3 ligase UBR5 significantly enhances the pyroptosis phenotype in cancer cells. Interestingly, the downregulation of RTN4 expression significantly facilitated a dynamic remodeling of ER membrane curvature through a transition from tubules to sheets, consequently leading to rapid fusion of the ER with the cell plasma membrane. In particular, the ER-to-plasma membrane fusion process is supported by the observed translocation of several crucial ER markers to the "bubble" structures of pyroptotic cells. Furthermore, α-MG-induced RTN4 knockdown leads to pyruvate kinase M2 (PKM2)-dependent conventional caspase-3/gasdermin E (GSDME) cleavages for pyroptosis progression. In vivo, we observed that chemical or genetic RTN4 knockdown significantly inhibited cancer cells growth, which further exhibited an antitumor immune response with anti-programmed death-1 (anti-PD-1). In translational research, RTN4 high expression was closely correlated with the tumor metastasis and death of patients. Taken together, RTN4 plays a fundamental role in inducing pyroptosis through the modulation of ER membrane curvature remodeling, thus representing a prospective druggable target for anticancer immunotherapy.